Afghan follow-through.

WHEN 15,000 CORPSES of the British Army of the Indus were freezing on the Hindu Kush passes in January 1842, Shah Soojah, the puppet Afghan king whom the British had installed in 1839, continued to rule in Kabul. As soon as the British were defeated, the Afghan coalition disintegrated, and no faction was strong enough to dislodge Shah Soojah from his Bala Hissar citadel.

Afghanistan is in a similar situation now. The Kabul Communists are supported by only a small minority of the Afghan population, and their foreign patrons have departed. But they are still entrenched in most of Afghanistan's provincial cities; they enjoy the Soviet Union's unqualified military, diplomatic, and economic backing; and, faced with defeat and revenge, they are determined to fight to the last.

Having mistakenly expected that the Najibullah regime would disintegrate soon after the Soviet departure, the Western media are now offended that the guerrillas have failed to provide the theatrical Fall of Kabul story and retaliate by disparaging them. "I would put even money on Najibullah's still ruling in Kabul in five years' time," pontificates Professor Fred Halliday of the London School of Economics. But to overrate Najibullah's strength now is as silly ,as it once was to exaggerate his weakness.

The mujahedin have not won yet because they are not trained soldiers; because, like their ancestors confronting Shah Soojah, they bicker; and because Pakistan and the United States have induced them into foolish enterprises such as the failed assault on Jalalabad. As Radek Sikorski reported in these pages recently, the mujahedin never planned to attack Kabul the moment the Soviets left. Only this summer will we see how strong they really are. If the guerrillas succeed in blocking the Salang highway, which is the only land supply route from the Soviet Union to Kabul, and if they match the attack on Kabul with a coup within the gates, then Najibullah would do well to keep a gunship ready for evacuation.

The Afghan jihad is unlikely to peter out. The Communist rule of terror and the horrors of Soviet invasion have unleashed passions that can only be appeased by the elimination of the Najibullah regime. It might take time. The Afghans, unlike our media, are not in a hurry. Most have relatives in the Communist-occupied cities and want to avoid hurting civilians. Reasonably, they prefer to wear the Communists down and dislodge them by bargaining and stratagem rather than by conventional battle, for which their enemies are better prepared.

Historical portents favor them. Shah Soojah survived the British defeat by a few months but was assassinated in April 1842, when he ventured out of the Bala Hissar to "his social bases," as Najibullah might put it today, in Stalinist jargon. Professor Halliday's new prediction is likely to prove as accurate as those he made in 1986 when he asserted that the Soviet army would never quit.